68929509721 has 2 divisors, whose sum is σ = 68929509722. Its totient is φ = 68929509720.

The previous prime is 68929509661. The next prime is 68929509793. The reversal of 68929509721 is 12790592986.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 65710195600 + 3219314121 = 256340^2 + 56739^2 .

It is a cyclic number.

It is not a de Polignac number, because 68929509721 - 2³³ = 60339575129 is a prime.

It is not a weakly prime, because it can be changed into another prime (68929509521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34464754860 + 34464754861.

It is an arithmetic number, because the mean of its divisors is an integer number (34464754861).

Almost surely, 2^68929509721 is an apocalyptic number.

It is an amenable number.

68929509721 is a deficient number, since it is larger than the sum of its proper divisors (1).

68929509721 is an equidigital number, since it uses as much as digits as its factorization.

68929509721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4898880, while the sum is 58.

The spelling of 68929509721 in words is "sixty-eight billion, nine hundred twenty-nine million, five hundred nine thousand, seven hundred twenty-one".